We have scanned in part of a magazine
article about the pump and the web comment starts on the right beside the
picture (in Netscape).

This is part of an article which appeared in a British farmers publication
called Practical Farm Ideas in the Spring 1997 edition. The full article
was 1 and one third pages with pictures. At that time we called it
the blow pump. (The pump can pump much higher than 4 meters).

Below you will find some web comment. Some didn't even look at
the web page before commenting but Peter Guerin certainly did. In fairness,
few have ever heard of a tromp, it is like an airlift pump working in reverse.
(His bit is at the end in Brown).

>Well, it wasn't my original post, but I have the web site for ya:
>
>http://w(our old web address)>
>Take a look. It seems to use the head of falling water, and
entrained
>bubbles to move water up another pipe like a bubbler tube.
>
>Maybe you'll get a different take on it than I did.

>
>Tim Wilson wrote in message <36E884B3.A1E35021@cmwave.com>...
>>If this discussion is about a hydraulic ram there are two moving
parts
>>the clack valve and the output check valve.
>>
>>Tim
>>
The device described is also known as a tromp
or trompe. It is an old technology that was used in blast furnaces and
mines in the past. The drawing at htp(old
web address) shows the top of the inlet pipe
level with the surface of the water.Another way to introduce air into the
water flow is to use a venturi towards the top of the inlet pipe. This
also allows the air to water ratio to be varied by controlling the air
inlet. The drawing shows the small diameter pipe below the water
level in the holding chamber.If the purpose was to pump air only the pipe
would terminate at the top of the chamber. This technology has been proven
for several hundred years and I think it may still be useful today in micro
hydro-electric applications. The air could be reticulated to a pneumatically
driven generator. This has the advantage of removing expensive turbines
and generators from damage by flood and corosion , and cutting transmission
losses between the point of generation and storage or use.We recommend a low-cost simple approach. In saying that,
there is nothing wrong with Peter Guerin's approach. However going deep
enough to give enough pressure to work that generator would prove too expensive
for the average user.